Thankyou for your answer. btw, it is posible for me to enjoy full opponent without lag?More opponents = more CPU load, simple as that.
If you meet the minimum requirements for AC, it should be possible to use 24 opponents without cpu occupancy slowdowns. Your framerate on the other hand is gonna dip pretty low at times (like low 10s) if all the AIs smoke the tires at once. Only applies to built in content, there is no level of PC that can handle all car/track mods with full grids of AI. Some of them are built extremely inefficiently.